Pump for pneumatic cleaners.



a. w. ALLEN. PUMP FUR PNEUMATIC CLEANERS.

APPLICATION FILED DEC. 1, 1913- G. W. ALLEN.

PUMP FOR PNEUMATIC CLEANERS.

APPLICATION HLEU DEC. 1. i913.

\NITN E5555 FNVENTUR w fle/mr W M @w! M J Patented Jan. 22,1918.

'G. W. ALLEN. PUMP FUR PNEUMATIC CLEANERS.

4 SHEETS-SHEET Patented Jan.22,1918.

INVENTOR WITNESQES wwfivez' UNITED STATESKPATENT OFFICE.

-GEORGE W. ALLEN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO B. F. STUBTEVANT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PUMP FOR PNEUMATIC CLEANERS.

Specification of Letters Patent.

Patented Jan. 22, 1918.

Application filed December 1, 1918. Serial No. 803,938.

To all whom it may concern:

Be it known that I, GEORGE W. ALLEN, acitizcn of the United States, residing at Hyde Park, Boston, in the county of Suf' folk and State of Massachusetts, have invented certaii'i 'new and useful Improvements in Pumps for Pneumatic Cleaners; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

The present. invention relates to pneumatic cleaners.

One Ulljutit of the invention is to im rove and rcor anizc the construction 0 the blower. nother object of the invention is to provide an improved outlet to adapt the cleaner for either suction or pressure work. Still other objects of the present invention are to improve the construction of the cleaner in certain other details pointed out in the claims, the advantages of which will be apparent to thoseslrilled in the art from the following description.

With the above objects in View, the invention relates to the pneumatic cleaner herein- 7 after described and particularly pointed out in the claims.

In the drawings which illus'i ate'the. pre ferred embodiment of the present invention, Figure 1 is a front elevation of the cleaner; Fig. 2 is aside elevation taken partly in section, the section through the front cover, the dust drum. the inlet and discharge-ens ings being a. central vertical section, while the sections through the fan 's'and the intermedi ate casings are taken substantially along the curved section lines 2-2 of Figs. 1l.and 13, respectively; Fig. 3 is an enlarged detail view taken on a central vertical section and showing one of the fan casing bolts in position: Fig. l is a. detail view of. one of the catches for holding the dust bag to the front cover: Fig. 5 is a front View of the inlet casing: Fig. 6 is a. side elevation of the inlet casing taken partly in section along the line '6-6 ,of Fig. 5; Fig. 7 is a'fi'ont viewof one Q of the expansion plates; Fig. 8 is a section taken along the line8--8 of Fig. 7; Fig. 9

is a. roar elevation of the discharge casing;

Fig. 10 is a. section along the line 10-10 of Fig. 9; Fig. lLis a front View of one of the intermediate casings; Fig. 12 isa section along the straight section line 12--12 of Fig. 11; Fig. 13 is a front View of one of the fans; Figsl l is a section taken along the straight section line I l-14 of Fig. 13; Fig. 15 is a detail View taken in rear elevation of the outlet; and Fig. 16 is a section taken along the line 16-46 of Fig. 15.

The pneumatic cleaner illustrated in the drawings is of the portable type with which a flexible suction hose and cleaning tool are employed. The cleaner comprises a dust collector 1, an air pump or blower 2 and an electric motor 3, all mounted together to form a self-contained cleaner Supported on rubber-tired Wheels 4 and provided with a handle 5 so that it may be conveniently. rolled from place to place. The dust collector is a cloth bag 6 inclosed in a dustbag chamber 7. The dust bag chamber 7 is formed by the removable front cover 8, the cylindrical dust bag drum 9 and. the inlet casing 10 of the blower. Back of the/dust chamber is the air pump or blower of the multistage centrifugal fan type which consists of four fans or runners .11, 12, 13 and 14. inclosed in the fan casing 15. The fan casing 15 is built of five sections. These sections are the inlet casing section 10, three intermediate casings or sections 16, 17 and 18, and the discharge casing or section 19.- Secured to the central portion of the rear face of the discharge casing is the motor casing 20.

ing and motor casing respectively; The fans are mounted on the motor shaft by means of elongated hubs 33 which are keyed to tho shaft. The motor is balanced by means of balancing rings 34 and 35 which have a mum ber of screw holes for thereception 'of set screws which are adjusted in and out to secure the proper balance.

The inlet, intermediate and discharge casings each have the outline of a short cyliIider, the outer periphery of which is a smooth,

unbroken, cylindrical surface so that when thesecasings are assembled to form the fan '80 inconnectio'n with casing,

broken cylindrical the fan casing has a-smooth and? exterior which greatly conduces, to the attractive appearance of the cleaner.

charge casings castmgs.

flat, the front and mediate casing are The inlet, interna'ediate and disare allmade of aluminum en the castings the rear face of, the inlet casi are finished, ng '10 is planed rear faces of each interplaned flat and parallel 1 and the front face of the discharge casing is laned flat. Becau et, intermediateand disch casing formin fan disch gether, eachamina of the mediate and held together of ii are ground and z'u-reamed to seemin the inlet casing.

bosses formed interna hi5 that the smooth, c

. fancasing is not bro ese assemblin -wheretheir heads 41 a cry of the rear wall oi The motor casing is in diameter. than the-'fan casin exposed, annular rear wall of t casing furnishes not only a suite t he'ads 41.,'-

; which th the bol se of this planing, the inarge casings fit toa layer or inlet, intercasing; The

are rigidly arge casings in perfect -alinement by means v ve assembling'bolts 40 through bolt holes in the the bolt holes are carefully e accurate alinement'of thec'asings. The front ends ofthe b threaded. in tapped.

which pass casings. The bolts olrs are portions of the b The bolts-pass through 11y of the casings so ylindrieal surface of the ken.- The only place at g bolts are visible is pear near the periphthe discharge casing. considerably smaller so that the e discharge his seat for, p but also fli-SP'CQ for the outlet 42 .to be directed rearwardly. This construction inwhich the asse extend inwardly from the d mbling bolts isc'harge' casmg inside 'of the cylindrical ,outline of the fan casing and in which the discharge outlet '40 s in the rear face of that portion of the tains the dust collector the cleanerpermits cleaner body w ich-conandfan to be a substantially. erfcct 'cylinderf'iwith a smooth and nnbro the cleaner. The

an exterior. wh 45 the distinctive and fan casing for the multistage fan built up ich. condnces to attractive" appearance of as above described not 'only has-an attractive-appearance, but is a construction which "ter and an. interio well Sl ck so a Fig. 6, the central particularly when-taken the expansion plates hereis a so very economical to casing 10. a mutated; in at .-f.iand 6. This fl te i r thin" j shell fitlioffmnch shorterlength tends substant entral opening 52-;

btorshaft and "fan pyrzivrdsananrinlar intake inlet casing conannular plate or v than diame' r'anmilar weh,51. The

ia-lly radially in: -for substantially through which hill) andp c As shown particu arly m portion 58 i this web,

wardly deflected along a 011; holes .jec't-in bearing 31.

The 'rearinoutlilof the bolt hol alike. casings is show is made: of a single which lies within the circle substanl ially dc scribed by the periphery of the fun 11, is flat. Beyond the periphery of the fan, the WBb lSClEflGCtECl 01' oflset rearwardly to form an uldlCllIlQd annular shoulder 54-. Beyond theshoulder 54, the web has a substanl iall v flat portion 55 and at its periphery 56 where it merges with theshcll is again rear- Fcnool'h curve, so that while the central fiat portion. 53 of the Web 51 is located substantially midway oi the length-0f the shell 50, the edge of the web merges with the shell 50 at its rear end. The fiat central portion 53 ofthe Web 51 forms with the partition plate 140 a fan chamber, and the annular edge portions 55 and 56 fo rm'with the curved marginal por tion of the partition plate a condensing cduct for the fan 11.

On the front of the web 51 are live equally spaced, radially disposed, forwardly pro g wings 60 which support a plate 61 which furnishes the mounting for the shaft The Wings 60 project snfi ciently forward from the faced the weh tilso that ample air passages are left hetweenthe web 51 and plate 61 for the air to flowzfrom't e .dust bag'c'hamber 7 into the fan intake passage 57,- In the. wings 60 are tapped screw holes 62 forthe reception of screws 63 bymeans of which a screen ring 64 is secured to the front of the inlet casing. The screen, rin a forwardly convex wire screen 65, which serves to hold the end .of the dust bag free from thefront of the inlet casing. Formed on the inside of the shell 50, at the places where the wings 6O join the shell jai'e five equally s aired, longitudinally extending, substantia 1y. semi-cylindrical lugs or bosses 70. Each pf these bosses is' drilled and tapped toireceive the reduced screw-threaded end -71 of' one of the assemblingbolts 40-.

and reamed to receive stemof the'bolt40.

iBack of the inlet casing 10 are the three intermediatecasings 16,17 and 18 which are all Theconstruction of the intermediate 11 in detail in Figs. 11 and 12 of the drawings. Each intermediate casin aluminum casting and has the outline of a cylinder of xpuch short-er len than diameter. Each intermediate casing consists of a thin, annular shell 80 having a smooth, cylindrical exterior surface and an interiora'ignular web 81 which extends inwardly froiilthe shell 80 about three-quarters of the distance to the center, Ieavflngin the center of. the web an opening 82.-. {The motor shaft and theiian hub 33 ext ten through the opening 82 which is safliciently larger than the hub to leave an an nular air intake passage 87 for thef-an. The central the end of the ground e is enlarged .part 83- of the [Web 81, which lies g 64 furnishes a support for ends of the fill? tially radial. which is discharged from the condensing 66' 20, The center of the web within the circle substantially described by the periphery of the fan 12, is substantially fiat and is spaced about midway between the ends of the casing. Beyond the pcri 'ahery 5 0f the fan 12, the Web is deflected to the rear to form an inclined annular shoulder 84. The annular 'iortion 85, which lies between the shoulder 4 and the shell 80, suhsten. tially flat except. at its extreme outer edge 10 Where it is deflected. hacltwzmlly at 86 to smoothly merge with the shell at its rem edge. The flat portion 83 of the web (:0- operatcs with one of the partition plates to form. a circular cl'lamber for the fan and lbjthe portion 85 cooperates with the. curved marginal. portion of the partition plate to form a condensing educt for the fan. On the front face of the web 81 a re formed ten equally spw'eed. reversing; vanes 90. The tops 26 or formed edges oi the vanes 90 are flush with the forward end of the shell 80. In. the unfinished casting from which the intermediate casing is made the is a little surplus metal on the top of ihe n'es Sit) and the l which i irmovi-ed when l list. This grh ezt of the flush with the finished front end of the shell The vanes 90 at 80 their outer ends merge Willi the shell substantially tangentially to the shell and curve inwardly until at their inner ends which ":ternoinote at the opening 82 they are suhstun- These vanes receive the air educt more or less tangentially from the fan. grachially check its tangential movement and discharge it through the central opening into the next fan. Formed on the inside of the shell 80 atthe losses of alternate vanes are fiv'e equally spaced, longitudiimlly extending, substantially send-circular logs or bosshs 91. which are drilled and reamed to 'reoeive'thc ground shafts of the bolts-s0. It

is to he I'ioted that these bosses 91 fornmd as they are at the bases of the vanes 90 require .Wery little extra, metal and moreover do not nterfere or obstruct the. passage of the air. Each of the vanes 90 is drilled and 66 tapped to provide screw holes 92 for the reception of" the screws by means of which partition plete is rigidly secured to the intermediate casing.

Back of the intermediate casings is the discharge basing 19, which isshown in de tail in '9 and 10.. This discharge C215 ingconsists of a thinv cylindrical annular shell 100 and :1 web 101 Which liorms the rear wall. of the fan ezising.. 'lhe web extends inwardly. from the shell 100 suhstnnoffset forwardly to form a shallow circular cavity 103 which forms the forward end of the motor containing chamber. The web has a central opening 1.0.4. just leie enou h for the passage of the motor she 't 30. no annular flange 105 projects .reerwerdly around the mouth of the recess 103 and is shouldered 41nd finished to form a: sent for the forward end of the motor Casing .20 which is rigidly bolted to the discharge casing. 'lhrough the upper part of the imnular fiat portion 102 of the Web are three bolt holes 106 for the reception oi. the bolls 1.07 which. secure the base of the cleaner handle 5 to the casing. Projecting from the forward face of the web 101 are bosses or lugs 108 which are drilled and tapped toreceive screws for holding one of the partition plates. .11: the unfinished costing from which the discharge easing made, some surplus metal is left on the forward ends of the shell 100 and. the bosses 1055v This surplus metal is rmnoved from the front face of the end planed list so that the ends of the one that and flush with the edge of Formed on tin inside of he .--:g evil substanl which are drilled and reamed ..o receivethe bolts 4.0. Two downwardly extendimg; 110 which are vast inti zi' with the din large easing furnish :1 support for the rear axle 111 of the cleaner.

"lot throi-igli the llilt'k of the discharge cesingr is an elongated nix-unto slot 120 through which the air is discharged. Fitted in this slot is split nipple 121 whirl is shown in (let-nil in Fi s. l5 and 1.0. This split nipple consists of :1 stationary and n movable [)Etlt- 122 and lZi'l fi't.Sl)((flli-Q.i}'. Tin, slzxliionzu'y port and in-m'ziiile port hav 1' iiiriily 4: 1-- lendingg senii-viri-nlui flanges and i2?) )'i po('li\'ol which. when the two pin-ls of ihe nipp g' are moved together, lfll'lll at short tapered rolls!- in'vr wlii n rmipllng may be fitted so that. th nir dischu red from the inn may he led through it hose ior cleaning where air under pressure is desired. The lixvilpzirt oi the nipplelflz has it flat plate or i'liingg e 1:26 which [its lIlSldO of and is se ('lll(l lo the mixing! 10 by means m sorews 127 The movable pert ol': the nipple 1.23 has :1 that n'l'i'llzllP-Hllillhd plate 128 which fits against the inside of the casing: 19 and. is lllUllllltIl to slide between guide hinges 129. The plane 1% is held snugly against the inside of the rear wnll of the casing by means of :1 spring 130. which hours against the tint contact plate rivelcil on the plutition plate 1&3. lWheu the two halves of'thr nipple are drawn together to receive :1 hoseeonpling, the plate 128 (loses ll of the slot 120 external to the nipple opening. When the cleaner is used for suction work, it is desirable to have a large discharge opening to prevent back pressure on the fans'antl under such circumstances the two partsot' the nipple are separated, the i'norable part bein moved to the opposite end of the slot from'tlie fixed part so that n-nc'ticaIly the entire area of the slot lQO is available for the exhaus Securcrl to the fronts of cache)? the three intermediate casings 16, 1-7 a1ltl'18 and the I yond the shoulder 147, the edge discharge casing 19 arethe four partition plates 1-11), 11-1. 1.42 and. 113. These partition plates are shown in detail in Figs. 7 and 8. Each partition plate consists-of a single p ece .of. sheet iron having through .llS center an opening 11+ just largeenough to loosely around the hub 33 of 'a tan, and

is spun or. deflected re'erwardly-to form the rear Wall 1 15 of the condensing. educt of the fan.'. Th extremelcdgefof the partition plate is bent to form a-short rearwardly extending tip 119. These partition plates. are

when combined with I very cheap to make and the cast sections of the fan casing make a composite fan casing which is chea to manufacture and verycasily assemb ed. The

fan casing is thus built up entirely. of the castings which form the cylintlrical inlet,

i intermediate and dischargesections I and 'ingsand the partition plates,

unnecessary to employ cored castings.

in Figs. 13 andl. Each fate consists of the fairly long hub 33 which'ts splined to the motor shaft and a cored sibstantially fiat thin circular fan portion 150. The circular bersQ the di ffns'ers an sheet metal partition Cplates. The fan chain the passages through which the air is led from one fan to another are all formed between the fan casing casteconomynf building notheentire fan casingot uncored castings afpd sheet metal plates-is. obvious. i p

The four fans or runnert 11,12, 13 and 14 are all alike and are .illu, trated in detail fan: portion comprises a circular rear late 151 which extends outward from the rear of the hub and is very slightlyinclined forwardly, and a number of curved blades 153 extendi'ng outwardly; from the hub between the rear and front plates 151 nd152. The

whole-fan is made of a. single aluminum casting, the air passages fi l-between 'the I blades 153 being cored in, the casting. The inner edge of the frontplete 152 is'lspaced through the webs of the casings. A shallow flangeloti projects forwardly from the fun a .just inside the inner edge of the casing web 'to prevent air leakage between the fanand -\\'0b. The air which enters the fan longi- The central portion 146 of the air through the fans, the passage of the V to the fan 13 will .be considered. The 'air enters the-inlet-opening in the fan 12 'flOVVlIlg in a direction substantially axially so that"it is Y The a flatannular front plate 152- away from the-hub to form an annular inlet 155 which is of substantially the same size as the annular'intake passages 57 and 87 tudinally through the inlet 155 is discharged from the periphery of the fan in a'directlon partially ,tangential and partially radial. 'llielioxvof air through the fans is indicated by, the arrowsjn' Fig.2. For the sakeof more clearly anddiagrannna'ticall illustrating the flow. of-air, the-section t irough the fans shown in-Fip'. i2 is taken so as not to intersect anyof the fan blades, such a. section being indicated by the curved section line 2-2. in Fig. 123 and the section through the intermediate casingsshown in Fig. Zis taken so asnot to intersect any of the vanes 90, sncha section being indicated by the'curved section line 2-2 in Fig. 11.

For the sake-of explaining the passage of air through the fan 12 and from'the fan 12 of the fan. The air is thrown outwardly by the centrifugal action of the fan blades 153. The substantiall fiat front and rear walls 150 and 151 of the fan converge slightly toward the periphery of the tent-so that the air passages 154 in the fan have-a substantlally uniform'cross section- The air, as it is discharged from .the'peripher'y of the fan, is flowing in a direction partially radial and partially tangential to thefan. The air thus dischar ed from the fan passes into the an nular t rout .(see Fig. .2) between the partition plate 141 and the annular shoulder 84.011 the weh 81 of the intermediate casing 16 The air, after passing through the throat 16G enters the difluser 161. The.

diffuser 161 is formed between the relatively diverging, v the web 81 and the partition plate 141. The function of the diffuser 1611s to transform a part of the'kinetic orwelocity energy of the'air, as it leaves the fun, into static pressure, This ,tranfiformation of the kinetic energy of the air int'ostatie pressure causes a condensation or diminution in- .the volume of the air. The increase incross section of the difiuser 161-is such that the velocitypressure transformation takes place without shock and --this contributes greatly to the e fiiciency. of'the fan; It is to be notedthat the difluser 161 forms an annular passage annular portions 85 studies of i surrounding the fan and devoidfof any vanes I or obstructions. It is found tlitit wlth the construction of the di-fi'user as herein illuss trated and .described the' noise incident to the blowing of 11161111118 reducedto auiiniq fit) "c'eive the. air which is flowing more or less "and vii is of jmrticular-limportance in'a gorta bl'e cleaner in which of necessity the Io; e'r'mnst be presentin the room 'or apart;

.Glu TedTpOillUnj86 615 12} web merges smooth- 1 with .the fiat wallififi of the diffuser til the inneriwallh'f the shell 80 of the intermediate citsing'll'i, so thatthe air is de flected without shock and is discharged flow ing rejcrwardly and tangentially into the space between? "thefi'front of the web of the intermediate casing 17 and thehac'k of the partition plate .141. The space between the webof the intermediate casing 17 and the partition plate l ll is, divided'int'o a number ofpassages 162 b means of the vanes'90. These'paesa'ges 16 ,as shown in Fig. 11, re-

taingentially and gradually lead it inward along a smooth curved path and discharge it flowing substantially radially-"inward at the mouth'of the intake passageiot the next fan 13'. The difluser 161" formed between the inletsection 1'0 and the partition plate 141 is identical in shape with that formed be tween --the"intermediate casin 's' and their partition plates. The'air discarged from the last/"fan 14 is directed into, the annular exhaust chamber formed inside the discharge casing 19 from whence it is discharged through'the discharge opening 42.

The dust bag druin 9 15 made of sheet iron bent into cylindrical shape. .This .drum is secured'at' its rear end inside of the inlet casingrifl by means offa number of rivets 17 0. efront end of the drum is similarly riveted inside of a drum ,collfir. 171 The lower edgeof-the drum collar is provided with a seat 172 through-which passes a bolt 173 on whichjis .swivel'efl the sin to front wheel ofthercleanef. e' annua'r front face'of the drum collar" 1171 is finished erfe'ctly plane a'nd flitt.- The front of the ust bag drum -is closed by the front cover 8, the

' rear fae'eof which is finished around the margin 'tofit (with the interposition of v a rubber g'asket 200) .agfiinst the front face 'ofthedruin' collar 171. Thecollar is removably held in place by-.meens of four bolts 17-1- 175,176 and-177, which are provided with thumb nuts 178. The two lower .bolts 174 and 1 7 5 are rigidly secured to the drum to. the drum 'colla-r 171 so that they may be lifted. The edge of the front cover 8 has four'ear's which are lace, the and the which sup ort its weikht. Then the swing bolts 176' and 1.77am dropped into their slots,

for securin the cover in place, the presence of any gui e flanges on the cover is unnecessary and the flat engaging surfaces of the drum ring and the cover need be simply me chined flat.

The suction hose, which is used with the cleaner is provided with a connection which fits within and is frictionally held in the inlet 180 in the front cover.- The-inlet 180 is provided with a cover 181 hinged at 182 above the. inlet. When the suction hose is disconnected, the cover 181 falls by gravity and closes the inlet. The closure of the inlet prevents the escape of dirt from the dust bag and particularly when the front cover is removed and lifted by its handle 183. The front cover also prevents overload of the blower and diminishes the noise in case the suction hose is takenofi while the blower is running. Without this front cover, if the. suction hose should be removed, a large volume of air would be freely ad mitted to the dust bagynot only overloading the motor, but also causing a loud whistling noise as it is drawn into the open inlet. As the cover 181 automatically drops when the hose is removed this is automatically pre vented. When the cleaner is to be used for pressure work, the front cover is taken off and turned upsidedown, which is permitted because the slotted cars at the top and b0ttom of the front cover are alike. In its invertedposition, the inlet cover 181 hangs open and freely admits air to the blower.

The mouth of the dust bag 6 is secured by a number of spring catches or clips indicated' generally by, reference numeral 192. Each. clip consists of an arm mil-securing it to the mouth ring 191 to which is hinged at 194 a hoolt 195. The hook 195 is normally spring-pressed toward the month ring by queens of the spring 196 against the tension of which it may be moved by a push button 197. The inside of the cover 8 is provided with an annular flange 198, the end of which has an inwardly directed beveled rib 199 for the hooks 195 to engage. The flat annular gasket 200 affords a. dust tight packing between the front cover and mouth ring and e. i

also between the front cover and dust drum collar. When the dust bag is to be emptied, the hose connection is removed from the inlet 180, the thumb nuts 178 are loosened End the front cover 8 and attached dust bag (Vere lifted out by means of the handle 183 andcarried out ofthe room for emptying. To remove the dust bag 6 from the cover 8 to empty it, the push buttons 197 are ressecl in, releasing the catches 192 so that t e dust bag may be removed. When the dust bag is to be put back, it is simply pressed into place. the hooks 195 sliding over and. catching behind the beveled lip 19.). While. the preferred embodiment of the present invention has been illustrated and described, it is to be understood that the present invention is not limited to its preferred embodiment. but may be embodied in other structures within the scope of thc'invention as set forth in the following clain1s5- l. The combination of a blower, adischargecasing'for the blower having an elongated oiiicning therein, a split nipple comprising two relatively movable parts which may be separated to uncover substantially wvhen thetwo halves the entire opening, one of said parts being lug may be uncovered when the two halves of the-nipple are separated and the opening may be closed except for the nipple opening are together, substantia'lly as described,

charge casing for the blower provided with an outlet having provision for receiving a pressure pipe connection and comprising two relatively movable parts which may be separated to enlarge the outlet opening when the pressure pipe connection is removed,

. substantially as described.

i. The combination. of a blower, a dis charge casing for the blower having an eloiv ignited opening therein and parallel guide flangcson the incident the casing at the, sides of the eloi'igated opening, a split nip ple comprising tworelatively movable parts which may be separated'to uncover substantially v.thc entire opening, one of said parts being provided with a closure plate fitting against the. inside of the casing betweentlic guiding ribs and a means for holding the plate against the inside of the casing-and permitting it to slide between the guide flanges, substantially as described.

5. -The combination of a plurality of fans' mounted on a common, driving shaft a fan ,casing com rising a cylindrical inlet casing having a p ane rear end face, a cylindrical discharge casing having a plane front end face, and one or more intermediate casings, each intermediate casing comprising a lexternally smooth cylindrical shell/ll 4' central portion dished to The combination of a blower, a CllS- circular fan chamber,

,.- the fans,- the rear face irin plane parallel faces and a, cen'tralweb lugs, and bolts passed through the'bolt holes within the shells for holding the casings rigidlv assembled, substantially as described. 6. The combination of a. centrifugal fan, and a fan casing, including a section consisting of a cylindrical shell and a central web extending inwardly from the shell and having a central opening therethrough, a second and adjacent section fitting against the similarly situated bolt holes in the other casa first section, and a sheet metal partition plate -r secured to the second scctionbetween it'and the first section, the web and partition plate being spaced apart at their central portions to forn a fan chamber and having relatively divergent annular surfaces beyond the 'pe riphery of the fan to form a diffuser therefor, substantially as described.

i 7. The combination of a plurality of centrifugal fans mounted on a common driving shaftand a fan casing including a plurality of sections, one section consisting of a substantially cylindrical outer shell and a central web extending inwardly trons-the outer shell and having a central opening thcrcthrough forming an intakefor one of the fans, the

second and adjacent substantially central web extending inwardly from the outer shell and having a central opening therethrough forming anintake for another fan, the front face of said web'being pro? vided with a pluralityflofinwardly extendsection consisting of a rear face of said web having its 1 receive a fan, a;

100 cylindrical outer shell and a ing vanes the top edgesof which are flush with one edge of tlie shell, and a partition plate secured to the tops of the vanes and cooperating with them to form a plurality of imvardly directed air passages and cooperating with the dished central portion of,

the web'of the adjacentsection to form a I substantially as describe '8'. Thecombination of a. plurality .of centrifugal fans'mounted on a commondriving shaftand a fan casing including aplu- 'rality ofi'sections, on'e sectlon consisting of a substantially cylindrical outer shell a'nd'a central web extending inwardly from the V outer shell and having a central opening therc'through forming an'intake for one of of said web'having,

itscentralportion dished, asecdnd' and adjace'nt section consisting of a substantially cylindrical outer shell andfl; central web extending inwardly from th -ol -lfifir shell and er the having. central Opening" tllere hro lgh ing manner-am m ce of said web being providccl with a p1uoutside of the cover, means for remova'bly rality of'invsoirolly extendin vanes, and a partition plate socured'to t e tops oiflm vcncsond cooperating with them to form a. plurality of inwardly directed air passages;

and co'pcmtin with the dished central por tion of the "We of thc adjcccnt section to form a circular? fan chamber, tho partltiou plate and the rear wall of the said dished Y web lacing relatively divergent beyond the periphery of the fan to form a cliiluser, said plctc'lieing of loss character than the in ternal diameter of the outer shells to afioifti an openin around the edge of the picks from the 'ilfuser to the inwardly directd air passages, substantially as described.

9. The combination of a plurality of can trifugcl fans and a fan casing consisting of a pluraliiyof circular fan chambers luving axial ii'rmii'cs. annular diffusers aroom the periphery of the far-"z chambers lmvin relatively {iiVBlgfiRiJ Wii'iio ono of said {ii ZEHE'EEIW'VEHS extending miiiaily beyond the otl lcr wall c1161 tciminafi'ng in a curved 110)?- tion to form a longitutiinally directed discharge f0? iillc diffuse-r" into tho next aijc com; fan Ciifliililfii saici casing having; air passages for "iwccwing the em from each (lifluser and loading it to the axial intake of the next fan, substantially as dcscribcd.

10; An intermediate section for a fsmcasing consisting of a substantially cylindrical outer shell anti a control web extending in wardly from-tho shell ami having 3, central opening thcretlirough, said web being provided upon one! side with a number of in? weirdly cxtcnciihg air directing vanes, the other side of the web having its central por- 'eion cliched so as to receive the fan between it and the planeof the adjacent cool of the Shell and. having its marginal port-ion where it joins the shell curved to meicgo with the shell, substantially as xieccrihcda 11. The. combination of a plurality "of ccnlirifu 'al fans mountcci on-wcommon ciriv. ing aha .s, a fan casing comprising an inlet casing a olischargc casing and one or more intermediato casingo, each xi-said. casings comprising :i substantiall 1 cylindrical outer shell having and faces fitting corresponding faces on the adjacent section,'. sonic-of amid sections being provided with. central Webs disposed substantially midway between the ends .shereoi and extending inwardly from the outer cylindrical shields, and a plurality of disl1-shapccl sheet metal partition plates of less diameter than the diameter-of the cections secured between said webs arid cooperating therewith to form fem chambers and air passages forllcacling the air from fan to fan, sub'stantially-ds described.

12. A portable pneumatic cleaner having a horizontal body, a cover for closing the front of the homily .ancl having an-inlct for '91: the cow:- and to be held open byvgmvity 1n another POSilllOIl oi the cover, 'subs ianconnectcd with the fan-recciving dis osed sub'stantially midway betwecn the vith t e shall, a secon 21ml adjacent septiong fitting against the first section and having a,

dust ladcn air, a, hingcfii (ion:- or flap on the scciiring tho cover in place so as to cause tho door to be closed by gravity m cm 11091121011 tially as dcscribexi.

13. 'Ifhc combination in a; portable 13mm matic cleginer of cylindrical horizontalbmiy having an open front end, a, circular cover closing said open end, a, plurality of fixed bolts extending forwardly from. the body and a plumlicy of swing bolts locatecl vertically above the 'fixecl bolts, ears on ihe edge of the front cover having downwardly i and upwardly opcnin iioxi of the fixed and t e swing bolts rcspec tivcly, said ears @ormittim the front cover to be positioned either rig t sido up or upside down; substantially as riescribed.

slots for the recap 8c '14: The combina'mon of a plmaulit of a cellil'iffl all fans moontocl on a common rim mg silo i and a fan casing including a SEQ- tion having u substanticlly cylindrical cute? I shell cmi an interior annularweb havingu' tifilililili opcning sold a fflH-ZEQElViIlQPOI'tIOH disposed substantially midway lictween tho ond'of the shcli and an; amnulm-fict portion Eortion by a rcarwaxdly inclined shoulder, t a fiat an? mulling-portion being deflected rearwardly at 5 its outer edge to smoothly merge with the shell, :1 second and adjacent section-fitting againot tho first section and having .a sub stantially cylincrical outer shell and 'ain intoxic! annular web provided with a central opening, and a partition-plate of less diameterthan tho internal diameter of said shells mountcd between the sections and no operating with the web of the first s sction to form a dclivcry chamber locctcd-substan ticily in the piano of rotation of the fan, substantially aadcsxcribcd.

Thc'oomloination of a, plurality of cenirifugal'fans mounted on a common driving shaft and a fancasin'g including a section having; a. substantially cylindrical outer shell and an iiiterior aimuiar web having a centml opcning, and a fali-ircccivingz;v portion on s of tho shell am: an annular fiat portion' connected with the fan-receiving portionby a recrwardly inclined shoulder, the fiat annular portion being deflected roan,- warcll at its outer edge to smoothly merge.

substantially cylindrical outer shell and an interior annular web provided with :pcentral opening, and a partition plate having an annular shoulder projecting forwardly, and

a marginal portion deflected rearwardly, the

partit on plate being mounted between the sections and cooperating with the web 01 the first ection to form an amhflar diffusing chamber for the fan, substantially as described. 1

16. The combination of a plurality of fans mounted on a common driving shaft, and a fan cusmg includlng a pl'urallty of sections some of which have central Webs and a plurality: bf sheet metal partition plates located between the se ctions and c0- opez'ahng with the m'ntml Webs to form fanvhnrnhers and an passages.

, GEORGE 'W. ALLEN.

\vltncsses GEO, E. S'ncnmxs. MIRIAM CLEMENT. 

